1. Field of the Invention
The present invention relates to an ultrasonic scanner for transmitting/receiving ultrasonic beams and, more particularly, to an ultrasonic scanner capable of acquiring three-dimensional data concerning objects within a living body to be examined for a three-dimensional medical diagnosis use.
2. Description of the Related Arts
In the medical field, the technique of ultrasonic diagnosis has been widely utilized. Such a medical diagnosis is performed by the use of an ultrasonic diagnostic apparatus composed of a mainframe of an ultrasonic diagnostic apparatus and a scanner including an array transducer. In practice, the diagnostic apparatus transmits ultrasonic beams and receives reflected echoes from objects in the living body by means of an ultrasonic scanner being in contact with a skin of the body, and thus acquired echo data are analyzed and processed by the mainframe of the diagnostic apparatus, so that the information of cross-sectional layer image and blood flow velocity, etc., are visually displayed in the form of a dynamic image.
Prior to describing in detail the structure of the ultrasonic scanner according to this invention, an explanation of a conventionally used convex type scanner will be made with reference to FIG. 1.
In accordance with this conventional ultrasonic scanner denoted with a numeral 10, an array transducer 12 disposed inside of a convex-shaped end portion of the scanner effects the transmission and reception of an ultrasonic beam. As is apparent from the drawing, this array transducer 12 is composed of a plurality of transducer elements 12a arranged along the end surface of the convex-shaped scanner 10.
At the curved end surface of the scanner 10 is disposed an acoustic lens 14 for focusing ultrasonic beam, and a matching layer 16 for matching acoustic impedance is disposed between the acoustic lens 14 and the array transducer 12. In addition, a backing layer 18 is disposed behind of the array transducer 12 for absorbing unnecessary ultrasonic waves.
With such a structure, the application of a drive signal to each transducer element 12a causes the ultrasonic beam to be transmitted in a direction normal to the upper surface of the element 12a. With this result, it becomes possible to acquire data concerning a fan-shaped two-dimensional area.
However, in accordance with the conventional ultrasonic scanner, it is hard to obtain information other than echo data concerning a two-dimensional area with the scanner stationary. To observe an affected organ within a living body three-dimensionally, it is necessary to intentionally move the position, or incline the angle, of the scanner by a manual operation.
When the scanner is moved or inclined by manual operation, it is highly difficult to observe the target organ at the optimum position and with the optimum angle, and also the data acquisition is disadvantageously disturbed. For such a reason, there has been a demand in a medical service field for an ultrasonic scanner capable of securely and accurately acquiring echo data concerning a three-dimensional area within the living body.
Further, according to advances in image processing techniques, it is now proceeding the development of an apparatus for visually and three-dimensionally displaying an image of an target in a three-dimensionally specified area within the living body. Even in the development of such apparatus, there has been expected the introduction of the ultrasonic scanner capable of acquiring three-dimensional information of the echo data.
This invention aims to solve foregoing drawbacks with the prior arts, and the object of the invention is to provide a three-dimensional ultrasonic scanner which is capable of acquiring data concerning a three-dimensional area within the body by specifying a position in three dimension without inclining the angle, or moving the position, of the scanner manually and intentionally.